Gongxianosaurus
- Sichuan, China ( Dashanpu Formation)
- Gongxianosaurus shibeiensis He et al. 1,998
Gongxianosaurus is a genus of sauropod dinosaur from the very original Jurassic of China. The only way is Gongxianosaurus shibeiensis. Gongxianosaurus is one of the most complete surviving original sauropods: The skeleton is largely known, only the skeleton of the hand and the majority of the skull is missing. The genus was described in a brief report in 1998 for the first time, an extensive scientific work is yet to.
The name Gongxianosaurus shibeiensis has the locality near the village of Shinan District in Gong (珙 县; pinyin: Gǒng Xiàn ).
Description
Gongxianosaurus is estimated at a length of 14 meters. Like all sauropods this kind moved away quadrupedal, as shown by the extended front legs, which accounted for 70-75 % of the length of the hind legs. The phalanges ( phalanges ) were sauropodentypisch short and robust, the Phalangenformel of the foot (the number of phalanges, counted from the innermost to the outermost beam ) was 2-3-4-5-1. All ended up on the outermost toe claws. Weight-saving lateral cavities of the vertebrae ( Pleurocoele ), as they showed later sauropods were missing, so that the vertebrae were quite massive. The sacrum consisted of three fused sacral vertebrae. The chevron bones were ungegabelt.
Typical of all sauropods was the low ossification of the limbs - the tendency to replace bone in the joints due to cartilage. Gongxianosaurus is the only sauropod, from the ossified lower ( distal ) tarsal bones have survived. This very original feature could indicate that split off from the ancestors Gongxianosaurus very early from the main line of development of the sauropods. Whether this feature in other early sauropods but actually missing or is simply not recorded as a result of fragmentary preservation is unclear.
System
Camelotia
Blikanasaurus
Gongxianosaurus
Eusauropoda
Since a detailed description is still pending, Gongxianosaurus has so far been considered only in a few cladistic analyzes. A recent analysis by Cecilia Apaldetti and colleagues ( 2011) suggests that Gongxianosaurus basal (original ) than Vulcanodon, Tazoudasaurus and Isanosaurus, but more derived ( advanced ) than the early sauropods Antetonitrus, Lessemsaurus, Blikanasaurus, Camelotia and Melanorosaurus.
Fund history
Gongxianosaurus comes from a locality near the village of Shinan in the Chinese province of Sichuan. The site includes purple pelites of Ziliujing Formation ( Dongyueshan Members ) on a layer member of Dashanpu lineup, and can be dated to the Toarcian. Thus the fossils younger than the age of the " prosauropods " Lufengosaurus, but are older than the well -known early sauropod Shunosaurus.
The fossils were discovered in May 1997 during a geological exploration. The started in the same month excavation applied to an area of about 200 square meters numerous fossils days, which include four fragmentary to complete Gongxianosaurus skeletons, but also remains of theropods with. 1998 saw the first description in the form of a short report by a research group led by He Xinluhai that the new Sauropodengattung Gongxianosaurus named and described. The excavation work at this stage were not yet complete, extensive investigations have been announced. 2000 appeared a second brief description of Yaonan Luo and Wang Changsheng. This first description in the style of a publication presented Gongxianosaurus as new sauropod that two years earlier published first description of He and colleagues is not mentioned. Also the content is largely consistent with the initial description of He and colleagues.
Luo and Wang report that different, found in Shinan bone may not provide shibeiensis to Gongxianosaurus, but belong to a second Gongxianosaurus type.